Gaynor Spencer

While Gaynor Spencer is officially on sabbatical, you will likely find the associate professor of Biological Sciences in her lab nearly every day, working on the projects for which she recently earned a Natural Sciences and Engineering Research Council of Canada Discovery Grant.

The $319,940 over five years will allow the associate professor to continue investigations related to how retinoic acid affects the nervous system in the Lymnaea stagnalis, or the fresh-water snail.

Her interest in this particular snail can be traced back to undergraduate work at Leeds University in the United Kingdom. Her supervisor wanted someone to culture the brain cells of this particular type of snail, which means taking neurons out and putting them in a dish. Her final-year research project naturally followed, as did a post-doctorate at the University of Calgary, where another researcher doing the same work attracted her attention. In fact, that Calgary colleague started her interest in growth cones, which are the structures found at the end of the neurites.

Why snails?

“I appreciated the way you could do things with the invertebrate brains that you couldn’t do as easily with the vertebrate brains,” in such animals as rats, mice, or chickens. The snail brain can be easily mapped, she explains, and the large neurons and their functions can be easily discerned, and pulled out consistently. This also means the transmitters and their role in some behaviours are known. Snail brains involve 30,000 or 40,000 neurons, versus a few hundred million in vertebrates (for example, a human brain has between 50 and 100 billion). The knowledge gained researching invertebrates can be applied to vertebrates, eventually at the human level.

Growth cones are integral to the research, since they help in the process of regeneration of cells by finding the way to make connections with appropriate cells. Spencer’s current work involves puffing retinoic acid on to the growth cones from a pipette, and watching how the growth cones react. Research indicates that in some cases, the retinoic acid helps make the growth cones connect. What they have found is that this process makes them turn, so they may act as a guidance molecule during regeneration, and therefore leading them to their targets, and in turn, aiding in regeneration.

Spencer connected her work with retinoic acid through discussions with colleague Bob Carlone, biological sciences chair, who works with spinal cord regeneration in newts. Carlone’s work has shown that retinoic acid is tropic, which is the directional aspect discovered in relation to the growth cones.
The eventual real-world application for the research lies in the possibility of treating degenerative diseases. Diseases and deficiencies involve degeneration of these neurons in the brain, so researchers are trying to find ways to prevent degeneration and study factors that may one day help in producing a regenerative process. One particular application for Spencer’s research is in the area of Vitamin A deficiency, which can affect pregnancy development. “Understanding the role of retinoic acid, which comes from Vitamin A, helps us better understand the problems associated with Vitamin A deficiency,” she says.

“My goal is to help build the knowledge base of how it is acting at the cellular level, and if it can be applied to the regenerative state. We are trying to determine if it guides the neurites to certain sites. Right now we are looking at single cells in a dish. Later, research will look at the intact animal, working with the intact brain.”

Spencer looks forward to replacing aging equipment in her 10-year-old lab, hiring more students, as well as a research associate/technician. She plans to have at least six students within the next few months, including those working in master’s and PhD programs.